Cardiac signals are often detected by ah electrocardiogram. Electrocardiography (ECG or EKG) is a transthoracic interpretation of the electrical activity of the heart over time performed by detecting the electrical activity from skin electrodes.
The ECG detects the activity by amplifying the small electrical changes at the skin of the chest that are caused when the heart muscle depolarizes during each heart beat. Changes in voltage attributable to the electrical changes are detected by two electrodes placed on either side of the heart.
It will be appreciated that there is a need in the art for improved techniques and devices for detecting cardiac signals.